Family doctor

A vaccine effective against four common forms of Human Papilloma Virus (HPV) has been developed and shows excellent ability (100% effective) to prevent cervical pre-cancer (CIN2/3) and cancer in situ as well as vaginal and vulvar pre-cancer that are related to these strains of HPV.

The vaccine known as GARDASIL ™ developed by Merck and Co and CSL is highly effective against HPV types 6, 11, 16 and 18. Full protection requires a course of three injections.

In women who are already infected by one of the above strains, the vaccine is effective in preventing infection with the remaining strains.

HPV types 16 and 18 are important co-factors that account for an estimated 70 % of all cervical cancers as well as some vaginal cancers. HPV types 6 and 11 account for an estimated 90 % of genital warts, so the vaccine will provide welcome protection against these as well.

Note that this does not mean that such a high percentage of carriers of the virus develop cervical cancer. In the vast majority of  woman who already  one or more of the HPV viruses will not develop cervical cancer , as the body mounts an immune response against the virus itself  and it may go away on its own .

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Between 50 to 80 % of women will have one or other strain of HPV by the time they are 50, but the vast majority will not develop cervical cancer. The mainstay of preventing cervical cancer has been and remains regular cervical smear tests which detect the early pre-cancerous changes in the cervix. Many women need more regular smear tests and /or  colposcopy because of changes brought about by these viruses.

Widespread uptake of this vaccine is likely to save many women from this sort of more intensive monitoring as well as actually greatly reducing the final incidence of cervical cancer and genital warts.

As cervical cancer is the second most common cause of cancer death in women on a worldwide basis, this vaccine represents a significant public health advance.

The vaccine efficacy studies in males are ongoing.

The optimum age for a good immune response to the vaccine is between 9 and 15 years old.

The vaccine is best given before any exposure to HPV but is also effective against the remaining strains in women who have already been exposed to one or other HPV strains.

It obviously makes sense for the population to be protected before they are sexually active, so that maximum benefit will be obtained from vaccination.

Side effects included local reactions and fever.

The main clinical trials of the vaccine are known as The Future 1 and Future 11.The age of participants in these studies  were 16 to 26.

The Vaccine has recently been approved by the FDA and is available free of charge on the immunisation schedule for girls aged 11 to 18.